1. Field of the Invention
The arts of sheet collating and sorting are well known arts that have been practiced for a very long time. A vast amount of technology has been developed, and many machines have been designed for arranging sheets of paper in a predetermined orderly fashion. With the development of fully automatic high speed printing machines, and the more recent advent of high speed copying and/or duplicating machines, there has been a steadily increasing demand for collating and sorting machines which are compatible with the large variety of printing, copying or duplicating machines presently available.
In order to better understand the development of the prior art in the above field, as well as the existing necessity for the present invention, one should have a basic understanding of the distinction between sorting and collating even though these terms have not been universally accepted as designations for the respective sheet handling methods hereinafter described. Generally speaking, in a machine in which a predetermined number of bins are to be utilized, the term sorting designates a method of sheet handling in which a plurality of successively identical sheets are fed into the predetermined number of bins until each bin contains one sheet, for example, page 1 of a twenty page booklet. Thereafter, another plurality of successively identical sheets are fed into the bins until each bin contains one of the second plurality of sheets, for example, page 2 of the twenty page booklet. This method of loading the bins is continued until each bin contains one copy of each of the twenty pages of the booklet in sequential order, so that at the end of the operation each bin contains a completed booklet. If ten bins are utilized, ten booklets will be simultaneously formed each having twenty sheets. Typically, in prior art sorting machines, notwithstanding the advantage of the sorting machine having on-line capability with a copying or duplicating machine, the completed booklets or collations must be removed at this time from the machine by hand, and the pages of each booklet are fastened together by any suitable means. Such means include conventional stapling, either by a manual operation or by feeding the booklet into an automatic jogging and stapling machine of which a variety of such machines are commercially available.
In the method of collating, a machine having a plurality of bins is preloaded with a predetermined number of identical sheets. After the bins have been loaded, a feeding means asociated with each bin, ejects one sheet at a time from each bin in order to form a collation (booklet) containing the desired number of sheets. In this mode of operation, each collation is formed individually, rather than all collations formed simultaneously. This is because the sheets are ejected from the bins in the same order as the numerical order of the pages that form the collation for each cycle of operation of the machine. Thus, for example, if it is desired to generate fifty booklets each having ten pages, each of ten bins is preloaded with fifty copies of a page of the booklet. The feeding means associated with each bin then operates to eject the ten pages, either simultaneously or successively, so that during one operating cycle of the machine, ten pages in numerical order are delivered to a receiving station. Thus, the fifty booklets are formed by running the machine through fifty cycles of operation in the above manner.
Notwithstanding the disadvantage of the requirement for hand loading typical prior art collating machines, one of the advantages of these prior art collating machines was the capability of automatically finishing each booklet as it is formed by placing any of a variety of stapling or stitching machines which are commercially available on-line with the collator.
It will thus be seen that the sorting technique is most efficiently utilized when it is desired to generate a small number of booklets each having a large number of pages, whereas the collating technique is most efficiently utilized when it is desired to generate a large number of booklets each having a small number of pages.
Another convenient way of easily recognizing the distinction between sorting and collating is to consider that in sorting the number of bins equals the number of booklets which can be formed regardless of the number of pages, and in collating the number of bins equals the number of pages in each booklet regardless of the number of booklets which are being formed.
In the methods described above, the sorting and collating machines are each illustratively chosen to have 10 bins available to hold 50 sheets of paper. With a sorting machine, the sorting technique would be selected to form a maximum of 10 booklets of 50 pages each. With a collating machine, the collating technique would be used to form a maximum of 50 booklets each having 10 pages.
Statistical anaylsis from typical in-plant duplicating rooms, commercial print shops, quick copy centers and other facilities in which a large volume of copying is carried out, reveals that the above chosen number of booklets and pages is representative of the vast bulk of individual operations carried out in the copying and duplicating field. This indicates that the prior art should have developed along the lines of a large variety of sorting and collating machines in the 10 bin range, or perhaps in the 10 to 20 bin range. Although some sorting and most collating machines have a number of bins within this range, the development of the prior art, and the commercial availability of products, has been directed more towards machines having large numbers of bins, particlarly so in the case of sorting machines. These machines are, of course, very complex in construction and operation, and highly sophisticated in the manner in which they can be programmed to generate multiples of booklets in a single operating cycle. They are also extremely expensive. All of these factors tend to make these machines attractive only to operators of very large commercial duplicating centers, or to print shops which handle extremely large volume jobs, e.g. 100 or more pages per booklet for a collating operation or many thousands of booklets having a relatively small number of pages for a sorting operation. The result of this situation, is that the average user of sorting and collating machines does not have freedom of choice to choose tthe best method of paper handling conducive to the size and number of booklets which he desires to form. The user must of necessity purchase both a sorting machine and a collating machine from such machines commercially available in the 10 to 20 bin range, or he must purchase either a larger collating machine or a larger sorting machine and use either machine efficiently for only one type of booklet formation and very inefficiently for the other type of booklet formation for which it wasn't designed. His only other choice is to farm out his sorting and/or collating jobs to outside print shops which can afford to maintain the necessary number and size of machines to handle all types of jobs. Of course, all of the aforementioned alternatives result in the individual paying a higher per unit cost for smaller jobs.
The present invention, as will be more fully appreciated hereinafter, is directed to the provision of a combined sorting and collating machine. The invention provides the capability of performing both of the above described sheet handling methods in a single machine, whose bin capacity is within the above enunciated range most suitable for the average user of sorting and collating equipment. The combined sorting and collating machine of the present invention will handle any sorting job in which the number of booklets to be formed is limited to the number of bins available (the number of pages per booklet being limited only by the sheet capacity of the bins). The machine will also handle any collating job in which the number of pages in each booklet is limited to the number of bins in the machine (the number of booklets which can be formed being limited only by the sheet capacity of each bin). It will be apparent that the machine of the present invention will meet all of the sorting and collating requirements of users within the range statistically determined to cover the vast bulk of such users.
Another advantage with this type of machine is that if machine is constructed with relatively large bins, it can be used in a sorting mode to form booklets having an extremely large number of pages, and can be used in a collating mode to form an extremely large number of booklets. This advantage is helpful for those occasional situations where a sorting or collating run extends beyond the range of a normal (average) run.
A still further significant advantage of the combined sorting and collating machine of the present invention is its capability of automatically loading sheets for the collating mode. The machine is operated in a semi-sorting mode in which identical sheets are loaded into the same bin, and successions of subsequent sheets are each loaded into respective successive bins. The resulting procedure provides an automatic loading of the machine which will thereafter be operated in a collating mode.
2. Prior Art
As previously mentioned, there are a few machines in the prior art which have a number of bins within the range of the number of bins in the machine of the present invention. One such machine is disclosed in U.S. Pat. Nos. 3,580,563 and 3,773,313, both issued to Ernest D. Bassett on May 25, 1971 and Nov. 20, 1973, respectively. These patents disclose a collator having a horizontal array of substantially vertically opening bins. Feeding means associated with each bin eject individual sheets from a stack of sheets contained in each bin, for the purpose of forming a collation of ejected sheets. Thus, by the definitions given above, this machine is a collator. The machine also includes a relatively complicated system of manually adjustable baffles which, in cooperation with a sheet conveyor, function to feed sheets from the conveyor into the individual bins. When the conveyor is run in a reverse direction from the direction in which it is run during normal collating, the bins of the machine can be automatically loaded prior to performing a collating operation. Thus, the machine disclosed in these patents is essentially an automatically loading collator.
The significant deficiency of the machine disclosed in these patents, and therefore the significant distinction between the machine of the present invention and that disclosed in the patents, is that no provision whatever is made for operating the prior art machine in a sorting mode. The Bassett machine is devoid of any concept or structure which would allow, or even facilitate with modification, the sorting operation to be carried out in this machine.
Another significant deficiency in the Bassett machine is that the only provision for ingress and egress of sheets to and from the machine is at one end thereof, which renders it particularly difficult to use the machine on-line with a copying or duplicating machine. As previously described, a significant advantage of any sorting machine is that it can be used on-line with a copying or duplicating machine, so as to sort the successive copies of the same document into different bins, and repeat the operation with successive documents. In sharp contrast to this deficiency, the machine of the present invention, at least in the preferred embodiment, provides for ingress of sheets at one end of the machine and egress of sheets at the other end, so that the machine can be operated on-line with a copier or duplicator. The inventive machine can thereby perform a sorting function in a most efficient manner. A corollary advantage of this construction over Bassett, is that by appropriate manipulation of the baffles and baffle controls which operate one way in a sorting mode operation, the machine of the present invention can also be operated to automatically load the bins preparatory to a collating operation. This is in lieu of manually loading the bins prior to the collating operation.
Thus, the machine of the present invention is so designed and constructed to perform functions neither contemplated nor possible with the prior art machine. The machine of the present invention also performs the same functions as those of the prior art machine with much less complicated structure, and in a more efficient manner. The invention achieves this, while at the same time achieving greater versatility and having provisions for automatic changeover from one mode of operation to another. This the prior art machine cannot accomplish.